Ministers received a Commons battering yesterday over widespread suffering caused by delays in payments under chaotic welfare programmes.

Work and Pensions Minister Mike Penning was forced to admit to a “completely unacceptable” backlog in work capability assessments by reviled contractor Atos.

Minutes later, he confessed to angry Labour MPs that assessments for personal independence payment (PIP) were taking “too long,” partly because of internal problems at the DWP, Atos and Capita.

He promised “urgent action” to combat delays, but there were protests when he went on to blame claimants for taking too long in returning application forms or incorrectly filling them in.

Labour shadow minister Kate Green complained that severely disabled claimants were waiting up to six months for a decision.

“Last year there were 229,700 claims for PIP, but decisions were taken on only 43,800,” she said.

Blaenau Gwent Labour MP Nick Smith challenged Work and Pensions Secretary Iain Duncan Smith over his original boast that a million people would be receiving the new universal credit by April.

But the cornered minister refused to give Mr Smith a figure for the actual number receiving the benefit. “The rollout has begun,” he said, adding that it would be completed by 2016.

Shadow minister Chris Bryant offered MPs a simple answer: “How many people are on universal credit? The answer is actually 3,200.”

Dundee West MP Jim McGovern complained that over 90 per cent of participants in the work programme in his home city had not been helped into work.

“I have a simple question for the minister. Why?”

Minister Esther McVey dodged the issue, but insisted that the work programme was “working well.”